In the related art, a mounting structure including an electronic component and a wiring board on which the electronic component is mounted has been used in an electronic device.
As such a wiring board, for example, Japanese Unexamined Patent Publication JP-A 2005-223226 discloses a composite multilayer board (wiring board) including a ceramic layer (inorganic insulating layer), a conductive pattern (conductive layer) that is disposed on part of a main surface of the ceramic layer, and a resin layer that is disposed on another part of the ceramic layer.
The inorganic insulating layer and the conductive layer have different thermal expansion coefficients. Thus, if heat is applied to the wiring board when the electronic component is mounted or operated, thermal stress may be generated between the inorganic insulating layer and the conductive layer. Accordingly, the inorganic insulating layer and the conductive layer may be separated from each other. As a result, disconnection may occur in the conductive layer, and thus, electrical reliability of the wiring board may be lowered.
Accordingly, there is demand for provision of a wiring board having superior electrical reliability.